The effect of ultrasonic turn-on sequence for dual ultrasonicassisted soldering

In this paper, the mixed powder of 40%Zn+60%SAC0307 is used as the solder, and a new type of dual ultrasonic-assisted soldering process is used to successfully achieve the interconnection of copper and aluminum dissimilar materials. At the same time, a series of studies have been carried out on the effect of the ultrasonic turn-on sequence for dual ultrasonic-assisted soldering. By comparing the mechanical properties and microstructure of the joints obtained under different process conditions, it is concluded that the best process of dual ultrasonic-assisted soldering is to turn on two ultrasonics at the same time. The shear strength of the joints obtained by the best process can reach 28.45MPa, and the microstructures of the Cu/interface and Al/interface are relatively uniform, and the IMC layer is relatively smooth. There are two IMC layers at the Cu/interface, namely Cu
5
Zn
8
(close to the Cu side) and CuZn
3
(close to the solder seam side), and a Sn-rich layer appears at the Al/interface.